A concavo-convex lens has refractive index

PHYSICS · Single correct · CBSE · Physics · Ray Optics and Optical Instruments · Ray Optics and Optical Instruments

Problem

1.5

, and the radii of curvature of its surfaces are

10\,\text{cm}

and

20\,\text{cm}

. The concave surface is upwards and is filled with oil of refractive index

1.6

. The focal length of the combination is (1)

18.18\,\text{cm}

(2)

15\,\text{cm}

(3)

22\,\text{cm}

(4)

28.57\,\text{cm}